Internet services provided by current Internet Service Provider (ISP) including fixed broadband and Mobile Network Provider (MNP) networks to individual subscribers are ‘flat’, usually based on peak bitrate charging. This is often extended by applying fixed price data buckets, especially in case of MNPs. The service offered is best-effort, providing ‘equal’ treatment for the packets of different users and applications through the network. The advantage is simple service agreements, simple network provisioning, and simple charging.
Such a setup is not always optimal from the perspective of either the subscribers or the network service providers. The best-effort networks, especially the MNP networks cannot provide any quality of service (QoS) guarantees for the traffic due to the shared, fluctuating resources on the radio. A differentiated packet or flow treatment may in many cases provide a better overall utility using the available network resources.
There are standardized methods for service differentiation. For mobile networks, a QoS architecture based on bearer concept is described in 3rd Generation Partnership Project (3GPP) technical specification 23.401. Also, a receiver (Rx) interface is specified in technical specification 29.214 to allow interaction between the content provider and the network. The BroadBand Forum has also defined the Broadband Policy Control Framework (specified in Technical Report 134) that meets the similar function of Rx. DiffServ (RFC4594), Virtual Local Area Network (VLAN) Tagging (IEEE-802.1Q) style packet markings can help provide QoS in these environments.
Traditionally, QoS is preferably network-initiated since initiation by user equipment (UE) is not preferred by the network operators to avoid fraud of QoS levels or inconsistencies. This requires network based classification of UE traffic. This classification is done usually by filtering on the header fields, or by deep packet inspection (DPI). Handling of specific traffic and the key performance indicators (KPIs) to fulfil is usually specified by Service Level Agreements (SLA). In general, there is also an economic consequence of using a certain traffic treatment, e.g., extra charging. The operator also runs policy and charging control to identify which users have access to a given service and how much they should pay for the service. Such services occur commonly in today's networks, like Interactive and Personalized (IPTV) in fixed broadband or the voice/video telephony both in fixed and mobile broadband.
Some proposals also allow the end-users to communicate their desires without economic consequences, though these proposals solve the trust issue by not changing the total allocation of the UE, only the relative share of the flows within that UE. The DPI based solutions have several problems. Firstly there is an incentive to masquerade traffic to achieve better service treatment. Secondly there is a trend to encrypt all the traffic of the user, often including protocol fields, which makes DPI harder and harder. Thirdly DPI might recognize the traffic of smaller OTTs wrongly or not at all, which might result in a competitive advantage for the large OTTs.
The service architecture outlined above has some other limitations, as well. One is that it may be applied for a limited number of applications that are specified in advance in the SLAs. The more dynamic, user controlled access to specific services is limited on one hand by the complexity of traffic classification (requiring dynamic signaling especially for encrypted and multiplexed traffic) and policy decision/charging. In terms of charging, there would be a challenge to provide a service that is easily controlled on the user side, which is one reason why bucket-based charging has become so popular. There are also problems in MNP networks with ensuring service guarantees for traffic requiring relatively high bandwidth guarantees due to the shared, limited, and costly radio resources.
The above problems have been addressed by the concept of soft service offerings, i.e., Gold/Silver/Bronze services. In this concept, the Gold users are given relatively higher resource shares than the Silver users, which in turn are given relatively more resources than the Bronze users. Higher preferential treatment comes with extra cost. One problem with these soft service offerings is that there is no strict service guarantees in congestion situations. Another issue with soft service offerings is that the received service is practically impossible to verify on the user side. This leaves the door open to potential user fraud, which it one reason why this type of service has not become popular.